Well it all depends on how you are working. Netbeans and Eclipse IDE's could do this for you using exploded deployments or writing an exploded archive in the deployments folder.
I'm sure (since i wrote it) that replacing an HTML file will not fire a reload in both those cases.
Now if you are producing an archive and deploying it then we don't know which file has changed and a reload will be required.
There is no such things as a reloadable parameter.
As for classes, reload is required (even if with 14 and fakereplace it will get better).